Additional Green Book GIS Download Information
Two download files are available for each NAAQS:
- Shapefile - includes boundary information for all of the NAAQS designated areas
- External Data File - contains the NAAQS area nonattainment/maintenance status and classification as of the Green Book posting date
The External Data File download is a compressed file containing external information in both xbase (dbf) and spreadsheet (xls) formats plus "ExternalFileData.txt" which describes the area attributes in the External Data File.
The External Data File can be linked to the shapefile with the composID field.
Download Table 1: Shapefiles Developed as Part of the Nonattainment Area Designation
The designation process has included the development of GIS shapefiles during the designation process for nonattainment areas since 2004, first used for the 1997 8-Hour Ozone standard revision. Table 1 provides links to the GIS shapefiles developed since 2004.
Download Table 2: Shapefiles Developed from Part 81 Table Descriptions
About the Shapefiles
The shapefiles were created using ESRI's GIS mapping software and can be used by geospatial mapping applications that support the ESRI shapefile format. ArcView, ArcGIS, and ArcExplorer (ArcExplorer is free from ESRI) can be used to view the shapefiles. Commercial and free third party software is available that can be used to view shapefiles.
Each shapefile is composed of multiple files compressed into a zip file. These files are required in order to be properly used by mapping software:
- shapefile.dbf: feature attributes
- shapefile.prj: projection file
- shapefile.sbn: spatial index of features
- shapefile.sbx: spatial index of features
- shapefile.shp: feature geometry
- shapefile.shp.xml: metadata in XML format
- shapefile.shx: shape index of the feature geometry
Nonattainment shapefile/map services are intended for mapping and visualization purposes only. EPA makes no claim that these shapefiles/map services represent the exact legal definitions of nonattainment areas. The legal definitions of nonattainment areas are available at 40 CFR part 81.